Background technology
Existing be used for carrying solid, liquid material or be used for the corrugated dual-wall hard PVC pipe of the underground preburied line of sheath, it is light because of having quality, rigidity and intensity height, and it is moistureproof, characteristics such as corrosion-resistant and be widely used in underground preburied line under the various normal temperature of sheath, to bear the soil layer of the top of sunkening cord in advance, the pedestrian, weight such as driving, and from ground surging force, but it is relatively poor because of resistance toheat, the thermal distortion vicat softening temperature is below 80 ℃, it but can not be used for the underground high-voltage power cable that sheath has heat to produce, so when the heat of high voltage power cable generation makes the double-wall corrugated pipe temperature be higher than 80 ℃, the ring stiffness of double-wall corrugated pipe declines to a great extent, so that can not bear soil layer on it, the weight of pedestrian and driving, more can not bear ground surging force, thereby forfeiture is to the sheath effect of high voltage power cable.Along with the raising of development in science and technology and the people's living standard demand to electric power, power industry heightens to demand that can heat-stable double-wall corrugated pipe thereupon, therefore improves the problem that protecting pipe thermal distortion vicat softening temperature becomes the task of top priority; People are just making great efforts to seek a kind of advantage that had both kept existing corrugated dual-wall hard PVC pipe, can meet cable guide quality product criterion of acceptability again, i.e. the double-wall corrugated pipe of the novel material of thermal distortion vicat softening temperature 〉=93 ℃.A kind of resistance toheat is good and cause people's attention with the akin chlorinated polyvinyl chloride resin of molecular structure (being the CPVC resin) of rigid polyvinyl chloride resin (being polyvinyl chloride resin), but when with the CPVC resin being material trial-production, be difficult to make double-wall corrugated pipe because of following problem having occurred, its reason is: 1) the easy moisture absorption of CPVC resin, the non-constant of processing characteristics, it is big because of melt viscosity to add man-hour, flowability differs from and need improve processing temperature, but because the decomposition temperature of processing temperature and material is very approaching, cause material breakdown easily, and decompose the gas that is produced and to play katalysis to the decomposition of material, cause the chain reaction that the chlorinated polyvinyl chloride resin raw material further decomposes; 2) the pre-plasticity of this material is relatively poor, so occur the coking of material easily in the long and narrow runner of double-wall corrugated pipe mold.Its result will cause the termination of production process.As making production can continue to go on reliably, its anxious problem to be solved is that how to prepare with the chlorinated polyvinyl chloride resin be the preformed material of major ingredient, that is with the chlorinated polyvinyl chloride resin be major ingredient the preformed material prescription and produce the production technique of the good double-wall corrugated pipe of resistance toheat with this material.
Summary of the invention
The present invention will overcome existing problem in the above-mentioned prior art, a kind of prescription and production technique thereof of chlorinated polyvinyl chloride double-wall corrugated pipe are provided, so that it have its prescription material can produce resistance toheat good, be rich in toughness, quality is light, intensity is high, can moisture-proof anticorrosive and the double-wall corrugated pipe product of good processability, its production technique is rationally reliable, can make the prescription material normally produce characteristics such as double-wall corrugated pipe continuously.
The prescription that chlorinated polyvinyl chloride double-wall corrugated pipe of the present invention is represented with weight part is:
Chlorinated polyvinyl chloride resin (being the CPVC resin) 50-80
Polyvinyl chloride (PVC) RESINS (being polyvinyl chloride resin) 20-50
Complex lead salt stabilizer 4.5-7.5
Stearic acid 0.6-0.8
Polyethylene wax 0.3
Paraffin 0.3
Calcium carbonate superfine powder 4-10
Anti-impact ACR 6-8
Also can contain red 0.15 weight part in the above-mentioned prescription.
The production technique of chlorinated polyvinyl chloride double-wall corrugated pipe of the present invention, carry out following step successively:
1) gets the raw materials ready by prescription;
2) above-mentioned getting the raw materials ready carried out high speed and mediated mixingly, mixing is time 10~13min, and mixing back temperature of charge is 120~135 ℃, temperature of charge is 45~55 ℃ after the low speed cooling and stirring;
3) above-mentioned mixing materials is pushed, the temperature of extrusion process is 170~185 ℃, and this temperature raises to exporting segmentation from import;
4) carry out compression molding with above-mentioned pressing material.
In the molded step of the extrusion die of chlorinated polyvinyl chloride double-wall corrugated pipe production technique of the present invention, the temperature of the internal orifice mould of its mould is that 195~210 ℃, the temperature of collar extension mould are 200~230 ℃.
Mixing materials extrusion process in the chlorinated polyvinyl chloride double-wall corrugated pipe production technique of the present invention and custom-designed conical double screw extruder, it contains the barrel of being with connecting joint, two conical screws that driven by the torque disengage gears installing in barrel, and, it is characterized in that: have one group of heating collar that temperature is different on the outer wall on the outer wall of barrel by the reduction box that shaft coupling connects.
The invention has the beneficial effects as follows: 1) the present invention has realized that with scientific and reasonable prescription and production technique with the good chlorinated polyvinyl chloride of resistance toheat be the double-wall corrugated pipe that material is made thermal distortion vicat softening temperature 〉=93 ℃, thereby solved the sheath problem of the pre-buried underground high-voltage power cable of being badly in need of in the current electric power industry development, it is compared with existing double-wall corrugated pipe, under same test conditions, promptly placed one hour under 80 ℃ the temperature, existing double-wall corrugated pipe can produce distortion, can't detect its ring stiffness index (promptly can't bear outer compressive load), and double-wall corrugated pipe of the present invention still keeps certain intensity, and its ring stiffness reaches 6.3kN/m
2More than, can satisfy service requirements; 2) the present invention is a major ingredient with molecular structure and the akin CPCV resin of polyvinyl chloride resin, and in getting the raw materials ready, add the thermo-stabilizer, lubricant, shock proof properties-correcting agent etc. of reasonable ratio, therefore can effectively get rid of and hinder for some reason and stop, guarantee the continuity of production process, thereby can produce chlorinated polyvinyl chloride double-wall corrugated pipe reliably, efficiently; This chlorinated polyvinyl chloride double-wall corrugated pipe not only resistance toheat is good, and kept still that the quality of existing similar double-wall corrugated pipe is light, rigidity and intensity height, and protection against the tide, protection against corrosion, characteristics that manufacturing cost is lower; 3) production technique of the present invention can also be prolonged and used existing processing units, and need not acquire new mechanical means in addition, so can remove to change the double-wall corrugated pipe product of different performance aborning according to the needs in market, not only convenient but also economical rationality.
Embodiment
The structure of the chlorinated polyvinyl chloride double-wall corrugated pipe of embodiment present embodiment can see from Fig. 1 and Fig. 2 that it contains outer wall 1a and inwall 1b, and leaves between the inside and outside wall enter this spatial air in moulding process.
The prescription of the chlorinated polyvinyl chloride double-wall corrugated pipe of present embodiment (each component is represented with weight part) is as follows: chlorinated polyvinyl chloride resin (being the CPVC resin) 50-80; Polyvinyl chloride (PVC) RESINS (being polyvinyl chloride resin) 20-50; Complex lead salt stabilizer 4.5-7.5; Stearic acid 0.6-0.8; Polyethylene wax 0.3; Paraffin 0.3; Calcium carbonate superfine powder 4-10; Anti-impact ACR 6-8.
CPVC resin in the above-mentioned prescription is close with the molecular structure of polyvinyl chloride resin, consistency good, and they can be with any mixed improving the processing flowability of material, but the big young pathbreaker of this proportioning directly has influence on the thermal distortion vicat softening temperature of product.The size of CPVC resin and polyvinyl chloride resin proportioning depends on the cl content of CPVC resin and the molecular weight distribution and the processing stability of polyvinyl chloride resin.If the cl content height of CPVC resin, then the content of CPVC resin reduces relatively in the proportioning; If the molecular weight distribution broad of polyvinyl chloride resin, then the content of polyvinyl chloride resin reduces relatively in the proportioning.By a large amount of tests, adopt above-mentioned proportioning, be that the CPVC resin is that 50-80 weight part, polyvinyl chloride resin are 20-50, can improve like this material processing characteristics, make to produce and continue normally to carry out, guarantee that again product thermal distortion vicat softening temperature 〉=93 ℃ is to meet the quality standard of cable guide product.
Thermo-stabilizer in above-mentioned the getting the raw materials ready, though can adopt the thermo-stabilizer of three salt or disalt, its large usage quantity, and need to add a large amount of inside and outside lubricants; Therefore select a kind of complex lead salt stabilizer FY-103 that self has lubrication in the present embodiment for use, it is buied from Hangzhou oil chemistry factory.
Stearic acid in the above-mentioned prescription, polyethylene wax (being O-PE) and paraffin are lubricant, wherein are that stearic acid lubricates based on interior, and lubricated beyond polyethylene wax and the paraffin is main.Though external lubricant is incompatible with material, it can be eliminated material and very easily stick to adhesion phenomenon on the processing units in extrusion, guarantees that the smooth and easy of material flows, and phenomenon does not remain in a standstill.Stearic acid is a kind of and the internal lubricant CPVC resin compatible, and it can alleviate the intermolecular phase mutual friction of CPVC, reduce the heat of friction that is unfavorable for forming process that produces because of friction.
Stearic acid, polyethylene wax and paraffin selected proportioning in prescription is to take into account flowability, non-stick property and the fusion rate of prescription material work in-process, and makes inside and outside lubricated effect balance, can guarantee to produce continuous, economical rationality.
Anti-impact ACR in the above-mentioned prescription is the LS-21 (being produced by Shandong Rui Feng macromolecular material limited-liability company) of outsourcing, and it is a kind of shock proof properties-correcting agent, is used for improving the fragility of the product higher because of the cl content of CPVC resin, that polarity is brought greatly.Though shock proof properties-correcting agent such as CPE, MBS, ABS etc. commonly used all can be used for the CPVC resin, not having but they have following shortcoming: CPE selected can reduce the thermal distortion vicat softening temperature, influence the final result of use of product, the weathering resistance of MBS and ABS is poor, easily aging, thereby has influence on the work-ing life of product; Though and anti-impact ACR price more expensive but it because of not containing unsaturated double-bond, so good weatherability, shock resistance might as well, and also help material plasticizing, reduce the temperature of processing.
Calcium carbonate superfine powder in the above-mentioned prescription adds as filler.
The prescription of present embodiment chlorinated polyvinyl chloride double-wall corrugated pipe, I, II, III, IV, V, five assembly sides (unit of each component is a weight part) listed in the available following table 1 are tested all and can be obtained effect preferably: the shock resistance of product and hoop rigidity height, thermal distortion vicat softening temperature obviously improve; The decomposition probability of material work in-process reduces significantly, has stopped the decomposing phenomenon of CPVC resin substantially, and it is also because of having good plasticizing capacity, flowability, so can guarantee that the production of double-wall corrugated pipe continues to carry out reliably.
Table 1
Also can add weight part in the above-mentioned prescription and be 0.15 red, make product become redness.As representative color, can make the double-wall corrugated pipe of sheath high voltage power cable be different from the double-wall corrugated pipe of other purposes with redness.
The manufacturing process of the chlorinated polyvinyl chloride double-wall corrugated pipe of present embodiment comprises the steps: successively
1) gets the raw materials ready by the prescription of above-mentioned chlorinated polyvinyl chloride double-wall corrugated pipe;
2) the high speed kneader is put in above-mentioned getting the raw materials ready, is at a high speed mediated mixing 10~13min, make temperature of charge rise to 120~135 ℃, put into the low speed cold mixer then and stir cooling, and when temperature reaches 45~55 ℃ blowing.
3) with the extruding of above-mentioned mixing materials, promptly mixing materials is added the twin screw extruder extruding that screw speed and shaper shaping speed are complementary, the temperature of pressing material is from 170 ℃ of import when axially rising to piecemeal of forcing machine exports 185 ℃; The differing temps of mixing materials when extruding helps promoting the plasticizing of material and the volatilization of small-molecule substance, brings out the probability that the CPCV resin decomposes thereby can reduce, and guarantees to produce and normally carries out continuously;
4) above-mentioned pressing material moulding also is about to pressing materials and introduces that typing pulls out chlorinated polyvinyl chloride double-wall corrugated pipe tubing in the corrugated pipe forming machine;
5) double-wall corrugated pipe after the moulding cuts through cutting machine, and on pipe-expanding machine to the one end enlarging can check warehouse-in.The flared end of double-wall corrugated pipe can make things convenient for the installation in use of each double-wall corrugated pipe to connect.
The temperature of the internal orifice mould of the extrusion die in the above-mentioned moulding process is set at 195~210 ℃, the temperature of collar extension mould and is set at 200~230 ℃.The temperature of a little higher than internal orifice mould of the temperature of collar extension mould can improve the glossiness of product appearance, reduces flat muscle and inwall and breaks, thereby improve lumber recovery.
Mixing materials extruding institute employing forcing machine is a conical double screw extruder in the present embodiment production technique, and its rotating speed and shaper speed thereafter are complementary; Its structure can see from Fig. 3, and conical double screw extruder 2 contains two conical screw 2a that install and driven by torque disengage gears 2d in barrel 2b; Torque disengage gears 2d connects reduction box 2g, imports power and motion into from external propulsion source (being represented Fig. 3) by shaft coupling 2f.During work, mixing materials enters from the charging opening of barrel, and through the extruding of conical double-screw 2a, 2c comes out from barrel right-hand member connecting joint; If at this moment connecting joint and extrusion die are connected as a single entity, then extruded stock can enter extrusion die.The axial force that produces on conical screw 2a in the extrusion process is by the thrust block balance in the thrust shaft block 2e on the frame.The present embodiment conical double screw extruder has four groups of heating collar 2h on the periphery wall of barrel 2b, the temperature range of each heating collar is respectively 170~175 ℃, 170~175 ℃, 175~180 ℃, 180~185 ℃ from left to right.
The used shaper of corrugated tube moulding is a track type shaper 3 in the present embodiment production technique, its structure can be seen from Fig. 4, at this moment extruded stock enters extrusion die 3g from the opening for feed 3b of forcing machine connecting joint 3a, then at linker 3a, advance to the right in the circular channel by the solid arrow direction in the distributor head 3c, and at distributor head 3c punishment fork, in inside and outside two circular channels, continue to advance to the right respectively, extruded stock in the wherein interior circular channel enters between forming module 3g and the cooling and shaping water jacket 3i, with the inwall 1b of formation chlorinated polyvinyl chloride double-wall corrugated pipe, and the extruded stock in the outer ring passage enters in the forming module 3g, to form the outer wall 1a of chlorinated polyvinyl chloride double-wall corrugated pipe; In the moulding process of the inwall 1b of double-wall corrugated pipe and outer wall 1a, the pressurized air that enters from the compressed air inlet 3f of distributor head 3c is blown in the forming module 3g (represents the compressed-air actuated flow direction with the solid arrow in the distributor head air flue Fig. 4), utilize compressed-air actuated air pressure, the material that is in the hot melt state that to extrude from the outer ring passage is close on the inner concave wall of forming module 3g, the duct 3j that is connected with pumped vacuum systems on the forming module 3g strengthens the be close to effect of this material to the forming module inner concave wall, form outer wall 1a, and behind cooling and shaping, the shape of outer wall can be in full accord with the concave shape of module 3g; Meanwhile, the stack thickness of the inside and outside layer material material base of being extruded by extrusion die produces squeeze greater than the gap between bellow forming module and moulding watercooling jacket, the two-layer material that is in the hot melt state tightly is bonded together, and behind cooling and shaping, forms trough.Product moves by the shaper forming module, is pulled out shaper from right-hand member.In the whole typing distraction procedure of chlorinated polyvinyl chloride double-wall corrugated pipe, forming module 3g enters interior rail by the outer rail of frame, and close up the beginning moulding at cooling and shaping water jacket 3h place, moulding finishes, and then gets back to outer rail (solid arrow on module 3g next door is represented the direction of its cyclic motion work and return) from interior rail; Water coolant then enters cooling and shaping water jacket 3h from the water-in 3d of distributor head 3c, behind the heat that shifts out inwall 1b, promptly from water jacket, comes out, and outside water outlet 3e flows out machine (flow direction of in aquaporin, representing water Fig. 4 with solid arrow).